You can use a Free Action when you deal damage with the weapon to deal Acid damage instead of the weapon’s normal damage type.
When you deal Acid damage with the weapon, you can spend 1 charge of Inspiration or Mana Flux to inflict Sickened 1 on the target.
When you deal Acid damage with the weapon, you can spend 1 charge of Inspiration or Mana Flux to inflict 1d6 Persistent Damage (Acid) per Tier of the weapon on the target.